This month, though, Facebook is under fire from a pair of environmental groups because Prineville's electric utility, PacifiCorp, generates most of its electricity by burning coal.

Criticism from Greenpeace and Change.org has attracted national attention within the information technology industry, catching Facebook off guard.

"This has been a big learning experience for us," said Facebook spokeswoman Kathleen Loughlin. "We're six years old. We've never owned a data center before. We've never owned land before."

The $200 million Prineville facility will employ three-dozen people when it opens early next year. Dozens more are now at work to build the 147,000-square-foot data center in Crook County, which had Oregon's highest jobless rate in December: 16.8 percent.

Facebook chose Prineville in part because of property tax exemptions that Oregon offers to industrial projects in rural areas. It also favored Prineville's dry, relatively moderate climate, which enabled the company to choose a low-cost, energy efficient cooling system for its project.

Data centers use massive volumes of electricity to run powerful computer servers that store data, video and photos. Google, Amazon, Microsoft and others have built, or are building, Northwest data centers to tap into the region's relatively inexpensive energy.

At the same time, projects here and around the world have attracted increasing attention from environmentalists concerned about the added energy demand these facilities create. That's particularly true when the power comes from coal, as most of PacifiCorp's electricity does.

"Facebook, by opening this center, is sending a signal: We're not quite done with coal yet," said Daniel Kessler, a Greenpeace campaigner in Oakland.

"We understand that the data center is being built. They already have a power service agreement," Kessler said. "This is really about where Facebook and the industry are going."

Coal-fired generators are a major source of carbon dioxide, which environmental activists and climate scientists say is warming the planet. Other Northwest data centers draw heavily on hydropower, which has takes its own environmental toll on the region’s fish.

Greenpeace set up a Facebook page urging the company to choose renewable energy, which has attracted 8,000 members.

Greenpeace credits Facebook for choosing an energy-efficient design in Prineville in a state with strong clean energy standards, he said. It isn't asking the company to abandon its plans, but does want Facebook to commit to using clean energy going forward.

"They can say to potential sites: If you want our business, increase the supply" of clean energy, Kessler said.

Facebook isn't ready to rule out utilities that burn coal, according to Loughlin, the company's spokeswoman. But she said Facebook is definitely paying attention to what it's hearing from the environmental community.

"This has really jumpstarted the conversation internally as to what, going forward, we're going to do," she said.